The sheet is the waterproof cover a therapist spreads over the bed before any gel is opened, so that the mattress and the room's own linen come through the evening untouched.
The sheet, in nuru, means one particular object: a broad waterproof cover the therapist brings in her bag and spreads across the bed before anything else is prepared. It is soft to the touch and quiet underneath a body, nothing like the crackling plastic the word might suggest, and with her towels laid over it the bed is as comfortable as before. Its single task is to keep a water-based gel away from the mattress beneath.
A studio can keep a dedicated table and launder its own linen. An outcall has only the bed the room provides, and that bed belongs to a hotel or to the owner of a flat. Towels on their own would betray it, since cotton is woven to absorb and would pass the moisture straight down into the mattress. The cover is the boundary that makes an ordinary bed fit for a technique built on gel, and without it nuru could not honestly be offered as an outcall at all.
When the session is over, the cover is folded away and leaves with her, towels and all. Nothing belonging to the room has touched the gel, and the bed can be made up again exactly as it was. In the morning a housekeeper finds a room like any other, and a guest in a rented flat hands back the keys without any conversation about the mattress.
All the client is asked to do is clear the way beforehand: lift the duvet, the throw and the spare cushions onto a chair, and leave the bed bare to its fitted sheet, so the cover can be drawn taut and held fast at each corner. A cover that creeps out of place mid-session means an interruption for everyone, which is exactly what that minute of preparation prevents. The step-by-step account is in the guide to the nuru shower and sheet, and why a water-based gel requires this protection is explained in its own entry.